‘The ocean is rising and it’s going to keep rising for quite some time’
A NOAA aerial photo shows damage caused by superstorm Sandy along the New Jersey shoreline. Click on the photo to see before and after images on the NASA EO website.
By Bob Berwyn
FRISCO — What until recently was a mostly academic discussion about sea level rise is starting to hit home — literally —as Americans watch devastating storms like Katrina, Irene and Sandy engulf cities and fundamentally alter the shape of coastal areas.
“What is very clear is, the ocean is rising and it’s going to keep rising for quite some time. The difference from last time is, now, there are a lot of people living on the coast,” said Margaret Davidson, acting director of NOAA’s Office of Ocean and Coastal Resource Management. Davidson’s powerpoint presentation is online here, and a video of her presentation should also be posted at the same place soon.
The consequences of rising sea level are likely to be enormous, given that the majority of the country’s population lives along coastlines, and those coastal cities generate a huge percentage of the country’s economic wealth.
“How do we begin to think about that? We’ve never had to think about relocating large populations,” Davidson said, addressing an audience of broadcast meteorologists and climate scientists during the annual Glen Gerberg Weather and Climate Summit in Breckenridge.
For now, the country is still in the adolescent phase of addressing the issue.
“We talk about it a lot, but we rarely put out,” Davidson said, adding that it’s time to grow up, advocating for a grassroots approach to awareness and decision-making.
“The tenor of the discussion has changed over the last few years, like when Vermont discovered with Irene that it was a coastal state,” she said, referring to widespread inland inundation from Hurricane Irene. And most recently, superstorm Sandy has helped reshape attitudes about rebuilding, she added.
Davidson made her case with humor, but also with startling directness.
“The Greenland ice sheet is not just melting, but collapsing at a rate that wasn’t even imagined by glaciologists 15 years ago,” she said, describing accelerated melting from underneath the ice sheet and the overall decrease in the reflectivity of the Greenland ice cap.
“As the ice sheet collapses, it’s shifting southerly,” she said, adding that some recent research suggesting a shift in the relative elevation of Greenland from north to south.
“Who knows, maybe the tipping point is not metaphorical after all,” she said. The massive changes in Greenland are dumping cold water into the ocean, upsetting the balance of upwelling and down-welling and even affecting the geography of the Gulf Stream.
“If you’re in the southeastern U.S., you have to be concerned. It’s becoming a more pressing issue on the east coast,” she said.
Given the realities of land-use patterns and planning in the U.S., Davidson said the best approach for tackling the challenges of protecting coastal communities is probably best handled at the local level.
The federal government can provide accurate and timely data, but local authorities on coastal communities must take the lead in preparing communities for the coming changes, she said.
Davidson compared the U.S. model with the Netherlands, where, along with spending billions of dollars on coastal defenses, the government has started a participatory process to relocate people out of marginal low-lying lands.
While that may be possible in some sparsely populated areas, it’s not a realistic scenario for major population centers like Miami-Dade, she said.
“You can structurally fortify and elevate, critical facilities … but we can’t really as a country think about fortifying and elevating individual homes, she said. “We’re going to pour a lot of concrete … but we’re dinking at the edges. Literally and metaphorically, it’s a marginal effort. We need to start thinking differently about how and where we site … we need to think, like the Dutch, about multiple lines of defense; dikes, wetlands and offshore berms.
“We’re making fundamental decisions about our footprint in the coastal landscape. Our decisions will affect how much damage we experience in the future,” she said.
All in all, the U.S. needs a multilevel strategy to address sea level rise, and that requires developing the kind of information normal people can use. That helps enable and empower people, leading to personal awareness and responsibility. if people understand how it’s going to affect them, they’re more likely to take action, she said.
Davidson described some successful examples of engaging individuals, for example in the Puget Sound area, where citizens are photographically documenting rising tides as they encroach on familiar landmarks with the King Tide photo initiative.
“It helps to visualize these things that you’re so familiar with, to make people understand that today’s flood is tomorrow’s high tide,” she said.
